import re

from fastapi import APIRouter, HTTPException
from pydantic import BaseModel, field_validator

from services import store

router = APIRouter(prefix="/api/drives", tags=["leds"])


class LedRequest(BaseModel):
    state: str

    @field_validator("state")
    @classmethod
    def validate_state(cls, v: str) -> str:
        if v not in ("locate", "off"):
            raise ValueError("state must be 'locate' or 'off'")
        return v


@router.post("/{device}/led")
async def set_drive_led(device: str, body: LedRequest):
    """Queue a locate-LED change. The poller (sole hardware owner) executes it."""
    if not re.fullmatch(r"[a-zA-Z0-9]+", device):
        raise HTTPException(status_code=400, detail=f"Invalid device name: {device}")

    queued = await store.enqueue_led(device, body.state)
    if not queued:
        raise HTTPException(status_code=503, detail="LED queue unavailable (Redis down)")

    return {"device": device, "state": body.state, "queued": True}